


Hunter, Hunted

by go_nuclear



Category: Haikyuu!!
Genre: Detective AU, F/M, Yandere, Yandere Oikawa Tooru, gore tw, i sure hope i got procedures right lmao, kageyama's a tsundere but is that really new, serial killer au
Language: English
Status: In-Progress
Published: 2020-10-26
Updated: 2020-10-27
Packaged: 2021-03-08 21:48:26
Rating: Teen And Up Audiences
Warnings: Creator Chose Not To Use Archive Warnings, Graphic Depictions Of Violence, Major Character Death
Chapters: 1
Words: 2,056
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/27213685
Author URL: https://archiveofourown.org/users/go_nuclear/pseuds/go_nuclear
Summary: You'd never planned for this. Never trained for the possibility that you'd be falling for a serial killer, yet here you were, staring into the eyes of Tooru Oikawa, knowing what he'd done but staying all the same.You weren't even sure if it was for the assignment anymore.
Relationships: Kageyama Tobio/Reader, Oikawa Tooru/Reader
Kudos: 26





	Hunter, Hunted

**Author's Note:**

> gore tw  
> this is my first haikyuu fic, so i hope i've done justice to everyone! enjoy~!

Your heart thumped in your chest, beating double time as you caught your breath behind a dumpster. Your head swam with thoughts of his words, the look in his piercing hazel eyes, the silver glow of his knife in the darkened warehouse...you had to bite your lip just to steady yourself.

For all the training you’d had in capturing people like Oikawa, nothing could prepare you for the singular sadism he displayed. Every picture you’d received of his victims’ bodies painted a grisly scene, his movements calculated and sweeping, doing enough to leave a trail but avoid getting caught. To your colleagues it was nothing more than another string of serial killings that needed to be solved, but to you it felt far deeper than the mystery the naked eye could see. 

It didn’t feel like someone who was scared of something, who had something to prove or demons to slaughter. No, this was the work of someone who liked killing because it gave them  _ control _ . It gave them the unbeatable rush of knowing that they’d brought someone to their knees and made them pray.

You could hear his footsteps drawing near, soft and strong, deftly avoiding the puddles left by yesterday’s rain. He thought he had the element of surprise, his cockiness keeping him from checking for your location before he advanced. 

“You know, darling, it’s so disappointing that you’d hide from me after all I’ve done for you,” He called, his footsteps slowing, your breath hitching as you gripped your pants, biting on your lip to try and slow your breathing. 

He clicked his tongue, footsteps pausing mere inches from your hiding place. “You can’t hide from me, darling. I  _ will  _ find you.” 

You heard something clatter beside you, too scared to direct your gaze to it until you heard his footsteps trail away. You slowly unfurled yourself, shaking as you crept toward the source of the sound. You’d half expected a knife, but instead found a credit card splattered with blood, the raised letters barely visible beneath the dried brown. 

Everything in your heart told you to hastily scrub off the blood, but your training betrayed you. You slipped the card into one of the inside pockets of your jacket, walking forward with a glaze over your eyes as cars whizzed past you, the sounds of the city sinking back in the further you strayed from Oikawa’s path. 

_ * _

_ “(Last Name), you’ve got a new assignment.”  _

_ Your head perked up, your hands scrambling to gather your paperwork before you followed Kiyoko to the captain’s office. It hadn’t been long since you’d submitted your last report, and you thought it strange to have one so soon.  _

_ As you pulled open Captain’s Ukai’s door you felt your heart lurch, your eyes immediately drawn to the well-kept mop of black hair belonging to your old partner. You schooled your face into a blank gaze, sliding into the seat beside Kageyama. _

_ “Glad you could show up, (Name),” Ukai remarked, playfully, leaning forward on his desk.  _

_ You could see the way the fabric shifted against his body, his collar rebelliously buttoned lower than it should be. You’d often found yourself wondering how someone as chaotic as Ukai had become the captain of your precinct, dealing more with detectives like you than the ones he called the “grunts on the streets”. Although, you couldn’t deny that you’d rather have him than someone as straight-laced as Kageyama, too scared to take risks that would damage the image he’d built for himself.  _

_ It was exactly that reason that you’d petitioned to get a new partner months ago, tired of being left in the dust of Kageyama’s penchant for doing everything on his own. Seeing him here now, after you’d solved a case far faster than he ever could, it made your back go up. Why would Ukai partner you with the last person you wanted to see?  _

_ “I know it’s sudden, but the two of you are the only ones I could think to tackle this one.”  _

_ You could feel Kageyama glance to you, but you kept your eyes forward. “What’s the assignment?”  _

_ “There’s been a string of murders around the prefecture, all with the same calling card. No one else’s been able to get close to figurin’ out who it is, so the reports all came to us.”  _

_ “So we’re their last resort?” Kageyama asked, his disdain for the situation more than evident.  _

_ “Something like that. In any case, you two are the only ones I figured could solve it before any more lives are lost.”  _

_ You felt your body tense. It was true that you and Kageyama had solved more cases in your year together than most of the other detectives had in half their careers, but you could barely stomach the thought of spending more than a few minutes with him after everything that had happened.  _

_ “Why don’t you just give it to Kageyama? He seems more than capable of doing it on his own,” You remarked dryly, crossing one leg over the other as you leaned back in the chair.  _

_ You could feel Kageyama’s eyes drilling into you, that same steely stare he gave you every time you fought. You could feel the waves of frustration and resentment radiating off of him, but you wouldn’t give him the satisfaction of meeting your eyes.  _

_ “It’s high time the two of you make up, and when better to do it than on assignment. Get to it.”  _

_ You left without another word to Kageyama, returning to your cubicle to start research before he could get a word in. As you slid into your chair you heard the shift of fabric, seeing the familiar shock of orange hair peeking over the edge of your cubicle.  _

_ “Kageyama looked  _ pissed _! What’d you do to ‘im?” Hinata asked, his thin eyebrows raised as he rested his forearms against the edge.  _

_ You shuffled a few papers on your desk and woke up your computer, singing as you typed in your password. “We got assigned to a case together.”  _

*

You didn’t remember when you’d returned to your apartment after dropping off the card, but when the morning came you were safely curled up in bed, changed into your pajamas with your hair still damp. It was strange, you half expected Kageyama to be in bed beside you, the small truce you’d reached one that tricked you into thinking things were like they used to be. 

The more you woke up the more clear your head became, Oikawa’s warning taking up residence in your head as you brewed a cup of coffee.    
_ You can’t hide from me, darling. I  _ will _ find you.  _

From the moment you’d first seen him you hated to admit that you were attracted to him. You hated yourself more and more for agreeing to that date, tricking yourself into believing, even weeks later, that nothing had come of it. 

As you held your mug you could feel the ghosts of his hands taking yours, his brown eyes gazing into yours as a small smile slipped across his thin lips. He’d kissed you then, telling you that he felt as if the night was endless, smooth as the winter winds that blew around you. You’d melted into him without even realizing it, feeling that sigh in your heart that you missed so much. 

A shiver ran down your spine. Not long after that first date he’d texted you to tell you that your problem with your sleazy landlord had been taken care of, giving you a knowing smile the next time he picked you up. You hadn’t realized exactly what he meant until you got a letter in the mail saying the complex was under new management, your stomach sinking as you realized just what you’d gotten yourself into.

The pieces had fallen together so quickly, but you kept going on dates with him to keep up appearances. You told Kageyama everything you could glean, but you found yourself holding something back every time you drafted a report. It was almost as if you  _ liked _ these sordid dates with Oikawa, giving them just enough information to move the case along without jeopardizing your personal scandal. 

But it had all changed last night, when you’d caught Oikawa darting into a warehouse, trailing a man you’d never seen before. You kept your distance, watching as Oikawa locked the door and checked the boarded windows, screams tearing through the night air within minutes. 

You were sure he hadn’t seen you, even as you made a beeline for your car, but he’d caught sight of you just as you disappeared into an alleyway. It was then that you’d heard his soft purr, promising that you’d meet again. 

*

_ “Quit glaring at everyone,” You hissed, your heels clicking against the tile floor of the crime scene, hands fidgeting in the pocket of your coat.  _

_ “They act like they’ve never seen a detective from another precinct before,” Kageyama muttered, keeping his eyes low as the two of you walked past another row of photographers and medical examiners.  _

_ You sighed and flashed your badge at the cops waiting by the crime scene tape, dressing in the necessary PPE before you entered the bloody scene. You weren’t one to have a weak stomach, but something about the murder rubbed you the wrong way. For all the training and schooling you’d had, you never thought blood could reach this far.  _

_ Nearly every inch of the white hotel suite was splashed with crimson, the body laid flat on the bed, as if he’d been positioned there for the police to find. The victim had been a salaryman, rich and powerful with a particular weakness for the seedy sides of things. Whoever had killed him was the person they’d been looking for, but any DNA evidence was more than sparse. He hadn’t cleaned up the scene, but he’d covered his tracks.  _

_ “Who could  _ do  _ something like this?” A voice to your right spoke, your eyes flicking over to the lead photographer. Her blond hair was messily tied back, camera slung around her neck, held in her gloved hands.  _

_ “A murderer,” Kageyama replied, stepping forward to investigate the carnage.  _

_ The photographer tried to sputter out a response, but stopped once she realized Kageyama had stopped paying attention.  _

_ “Sorry about him.” You offered her a smile before following Kageyama, carefully crossing the room to the body.  _

_ He’d been killed with a slice to the throat, deep enough to cut through the jugular and nearly hit the spine. It had been a miracle that whoever had done the deed didn’t leave a trail of blood in the wake of his escape—although this seemed far too calculated for them to make such a simple mistake. The more you observed the scene the more you felt you knew about the killer, from the precise way he’d killed the victim to the presentation of his kill, this was a man who never did anything without reason.  _

_ And you didn’t like to think that you were the same way. _

*

You finished your work in a daze, hardly talking to anyone else in the precinct. You waited with bated breath for the ping of a text from Oikawa, scared that you’d end up in the same place as that man in the warehouse. You were the only one who truly knew him, and the only one that knew of your affair. As far as Kageyama and Ukai knew your information had come from a trusted source that wished to remain anonymous, someone close to Oikawa but lacking the full story. 

As you left work you felt your phone buzz, your stomach lurching as you saw Oikawa’s name on your screen.    
_ Dinner tonight, darling?  _

You had to say yes. You boarded the subway, staring down at your keyboard, trying to figure out why the feeling of excitement had burrowed into your bones. It was the same feeling you ‘d had when Kageyama picked you up for dinner, dressed in a crisp shirt holding a bouquet of flowers. But his plastic-wrapped roses weren’t Oikawa’s multi-colored dozens, tied with a ribbon and presented in a vase. Everything about him seemed... _ more _ than anything you’d experienced before. You knew his true nature, but you still loved the way he treated you.

_ Of course. What time?  _

_ Eight?  _

_ Perfect.  _


End file.
